Why does "ps -aux" complain about a bogus '-'?
-According to the POSIX and UNIX standards, the above command asks to display
-all processes with a TTY (generally the commands users are running) plus all
-processes owned by a user named "x". If that user doesn't exist, then ps will
-assume you really meant "ps aux". The warning is given to gently break you of a
-habit that will cause you trouble if a user named "x" were created.
-
+ According to the POSIX and UNIX standards, the above command asks to
+ display all processes with a TTY (generally the commands users are
+ running) plus all processes owned by a user named "x". If that user
+ doesn't exist, then ps will assume you really meant "ps aux". The
+ warning is given to gently break you of a habit that will cause you
+ trouble if a user named "x" were created.
Why don't I see SMP (per-CPU) stats in top?
-You didn't enable it. Press '?' for built-in help or read the man page. Per-CPU
-stats are disabled by default because they take up too much space. Some Linux
-systems have hundreds of CPUs.
-
+ You didn't enable it. Press '?' for built-in help or read the man
+ page. Per-CPU stats are disabled by default because they take up too
+ much space. Some Linux systems have hundreds of CPUs.
Why do long usernames get printed as numbers?
-The UNIX and POSIX standards require that user names and group names be printed
-as decimal integers when there is not enough room in the column. Truncating the
-names, besides being a violation of the standard, would lead to confusion
-between names like MichelleRichards and MichelleRichardson. The UNIX and POSIX
-way to change column width is to rename the column:
-
- ps -o pid,user=CumbersomeUserNames -o comm
+ The UNIX and POSIX standards require that user names and group names
+ be printed as decimal integers when there is not enough room in the
+ column. Truncating the names, besides being a violation of the
+ standard, would lead to confusion between names like MichelleRichards
+ and MichelleRichardson. The UNIX and POSIX way to change column
+ width is to rename the column:
-The easy way is to directly specify the desired width:
+ ps -o pid,user=CumbersomeUserNames -o comm
- ps -o pid,user:19,comm
+ The easy way is to directly specify the desired width:
+ ps -o pid,user:19,comm
Why is %CPU underreported for multi-threaded (Java, etc.) apps?
-You need to upgrade to the 2.6.10 kernel at least. Older kernels do not provide
-a reasonable way to get this information.
-
+ You need to upgrade to the 2.6.10 kernel at least. Older kernels do
+ not provide a reasonable way to get this information.
Why do ps and top show threads individually?
-The 2.4.xx kernel does not provide proper support for grouping threads by
-process. Hacks exist to group them anyway, but such hacks will falsely group
-similar tasks and will fail to group tasks due to race conditions. The hacks
-are also slow. As none of this is acceptable in a critical system tool, task
-grouping is not currently available for the 2.4.xx kernel. The 2.6.xx kernel
-allows for proper thread grouping and reporting. To take advantage of this,
-your programs must use a threading library that features the CLONE_THREAD flag.
-The NPTL pthreads provided by recent glibc releases use CLONE_THREAD.
-
+ The 2.4.xx kernel does not provide proper support for grouping
+ threads by process. Hacks exist to group them anyway, but such hacks
+ will falsely group similar tasks and will fail to group tasks due to
+ race conditions. The hacks are also slow. As none of this is
+ acceptable in a critical system tool, task grouping is not currently
+ available for the 2.4.xx kernel. The 2.6.xx kernel allows for proper
+ thread grouping and reporting. To take advantage of this, your
+ programs must use a threading library that features the CLONE_THREAD
+ flag. The NPTL pthreads provided by recent glibc releases use
+ CLONE_THREAD.
What systems are supported?
-Linux 2.4.xx and 2.6.xx are commonly tested and expected to work well. SMP is
-well supported. Multi-node cluster views require a multi-node /proc filesystem;
-without that you will see a single-node view.
-
+ Linux 2.4.xx and 2.6.xx are commonly tested and expected to work
+ well. SMP is well supported. Multi-node cluster views require a
+ multi-node /proc filesystem; without that you will see a single-node
+ view.
Where to I send bug reports?
-You may use the Debian bug tracking system or send your report to
-procps@freelists.org (no subscription required) instead.
-
+ You may use the Debian bug tracking system or send your report to
+ procps@freelists.org (no subscription required) instead.
Why are there so many procps projects?
-The original maintainer seems to have had little time for procps. Whatever his
-reasons, the project didn't get maintained. Starting in 1997, Albert Cahalan
-wrote a new ps program for the package. For the next few years, Albert quietly
-helped the Debian package maintainer fix bugs. In 2001, Rik van Riel decided to
-do something about what appeared to be the lack of a maintainer. He picked up
-the buggy old code in Red Hat's CVS and started adding patches. Meanwhile,
-other people have patched procps in a great many ways.
-
-In 2002, Albert moved procps to http://procps.sourceforge.net. This was done to
-ensure that years of testing and bug fixes would not be lost. The major version
-number was changed to 3, partly to avoid confusing users and partly because the
-top program had been redone.
-
-After development essentially stopped on sourceforge.net, in 2011 the project
-found a new home at http://gitorious.org/procps. This represents the Debian,
-Fedora and openSUSE fork of procps. To avoid confusion and potential name
-clashes the package is now known as procps-ng (next generation), the version
-number was raised to 3.3.0 and the library soname changed to libproc-ng-3.3.0.
-
+ The original maintainer seems to have had little time for procps.
+ Whatever his reasons, the project didn't get maintained. Starting in
+ 1997, Albert Cahalan wrote a new ps program for the package. For the
+ next few years, Albert quietly helped the Debian package maintainer
+ fix bugs. In 2001, Rik van Riel decided to do something about what
+ appeared to be the lack of a maintainer. He picked up the buggy old
+ code in Red Hat's CVS and started adding patches. Meanwhile, other
+ people have patched procps in a great many ways.
+
+ In 2002, Albert moved procps to http://procps.sourceforge.net. This
+ was done to ensure that years of testing and bug fixes would not be
+ lost. The major version number was changed to 3, partly to avoid
+ confusing users and partly because the top program had been redone.
+
+ After development essentially stopped on sourceforge.net, in 2011 the
+ project found a new home at http://gitorious.org/procps. This
+ represents the Debian, Fedora and openSUSE fork of procps. To avoid
+ confusion and potential name clashes the package is now known as
+ procps-ng (next generation), the version number was raised to 3.3.0
+ and the library soname changed to libproc-ng-3.3.0.
What is being done to procps-ng at its new home?
-All programs are in the process of being modernized, both in terms of coding
-style and supporting documentation. Autotools have been integrated and the
-library API has been expanded with many new fields supported such as control
-groups, supplementary groups, etc. The top program has been rewritten offering
-many new capabilities while providing performance improvements up to 300%.
-
+ All programs are in the process of being modernized, both in terms of
+ coding style and supporting documentation. Autotools have been
+ integrated and the library API has been expanded with many new fields
+ supported such as control groups, supplementary groups, etc. The top
+ program has been rewritten offering many new capabilities while
+ providing performance improvements up to 300%.
Why does ps get signal 17?
-No ps release has ever had this problem. Most likely your system has been
-broken into. You might want to install a more recent version of the OS. If
-you'd rather take your chances, simply upgrade procps.
-
+ No ps release has ever had this problem. Most likely your system has
+ been broken into. You might want to install a more recent version of
+ the OS. If you'd rather take your chances, simply upgrade procps.
projects / procps-ng / commitdiff